Egypt's Islamist President said on Thursday he backed peaceful protest but not attacks on embassies after Egyptians angry at a film deemed insulting to the Prophet Mohammad climbed into the US embassy in Cairo and tore down the American flag.

Highlighting the challenge facing
President Mohamed Mursi, protesters threw stones at police blocking their approach to the fortress-like embassy near Tahrir Square, even as his televised address was broadcast on Thursday.

Police fired tear gas back.

Hundreds of demonstrators had gathered in the area, but a smaller group of those joined battles with police.

The health ministry said 224 people were injured, according to the state news agency, and 23 people were detained.

Many Muslims believe depicting the Prophet is blasphemous. In the past, cases where the Prophet was insulted have stirred condemnation and protests across the Islamic world.

"Expressing opinion, freedom to protest and announcing positions is guaranteed, but without assaulting private or public property, diplomatic missions or embassies," said Mursi, an Islamist who is Egypt's first freely elected President.

He pledged to protect foreigners in Egypt, a comment he repeated during a news conference in Brussels where he was making his first European trip to build ties with European Union states and secure support for Egypt's embattled economy.

The EU offered Egypt economic aid of up to 700 million euros ($902.19 million), following Arab Gulf states and the US pledging support for the country's battered economy.

The US embassy assault will test Mursi's handling of ties with the West and particularly the United States, a close ally of Egypt under ousted President Hosni Mubarak and which has long been wary of Islamists.

Washington is a major aid donor to Cairo.

Mubarak was toppled in popular protests last year.

US President Barack Obama told a Spanish-language network that Egypt's Islamist-led government should not be considered a US ally "but we don't consider them an enemy."

US secretary of state Hillary Clinton said the film was "disgusting" and that the US government had nothing to do with it.

Mursi also needs to strike a balance by addressing the anger over a film that portrayed the Prophet as a philanderer and religious fake, enraging Muslims across the region.

Call for US actionThe US ambassador to Libya and three other staff were killed when the US consulate in Benghazi was attacked on Tuesday. Since then, police have fired tear gas at protesters in Tunisia and demonstrators stormed the US mission in Yemen.

"All of us Egyptians reject any form of attack or insult to the Prophet," Mursi said, while offering his condolences over the killing of the US ambassador and diplomats in Libya.

Mursi said he had spoken to Obama on Thursday.

"I affirmed to him the need for deterrent legal measures against those who want to damage relations between peoples, and particularly between the people of Egypt and the people of America," he said.

In another statement, Mursi said he expects "assurances from the US government to prevent any infringement on the sacred".

At least one of the promoters of the film Innocence of Muslims is an Egyptian Coptic Christian who lives in America. Clips of the film have circulated on the internet for weeks.

The clashes flared in Cairo on Wednesday and protesters hurled rocks at police and dodged teargas canisters again on Thursday.